Experimental Study on the Milling of a High Strength Titanium Alloy

Abstract:

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A series of experiments were carried out on normal and high speed milling of a high
strength titanium alloy (TA15). TA15 is a close alpha titanium alloy strengthened by solid solution with Al and other component. It is often used to make large structural parts in airplane and welded parts subject to heavy load. The tool life of several typical types of cutter commonly used in the milling of titanium alloy was studied by the orthogonal experiment design method. After multi-element regression analysis, the empirical equation of the tool life was stablished. The milling force and temperature were measured under different cutting conditions and tool wear status. The knowledge is useful to further understand and analysis of the cutting mechanism, machining quality and tool wear. The study on the machined surface integrity includes the following content: surface roughness, metallographic examination, work hardening and residual stress.

Abstract: The design for orthogonal cutting experiment is made according to the characteristics of a
new kind of nickel-based super alloy. The machinability of this new material in milling and drilling
operations, including cutting force and tool wear, has been researched through experiments and then
the empirical formulas of cutting force in milling and drilling have been presented. The research is
useful in selecting the tool geometry and cutting parameters for machining the new material in
practice.

Abstract: During gray cast iron cutting, the great rate of mechanical energy from cutting forces is
converted into heat. Considerable heat is generated, principally in three areas: the shear zone, rake
face and at the clearance side of the cutting edge. Excessive heat will cause undesirable high
temperature in the tool which leads to softening of the tool and its accelerated wear and breakage.
Nowadays the advanced ceramics are widely used in cutting tools. In this paper a composition
special of Si3N4 was sintering, characterized, cut and ground to make SNGN120408 and applyed in
machining gray cast iron with hardness equal 205 HB in dry cutting conditions by using digital
controlled computer lathe. The tool performance was analysed in function of cutting forces, flank
wear, temperature and roughness. Therefore metal removing process is carried out for three
different cutting speeds (300 m/min, 600 m/min, and 800 m/min), while a cutting depth of 1 mm
and a feed rate of 0.33 mm/rev are kept constant. As a result of the experiments, the lowest main
cutting force, which depends on cutting speed, is obtained as 264 N at 600 m/min while the highest
main cutting force is recorded as 294 N at 300 m/min.

Abstract: Five-axis milling is widely used in machining of complex surfaces parts. Part quality and productivity are extremely affected by cutting force and tool wear, especially thin-walled complex surface, such as turbine blade. Although extensive research has been conducted on cutting force and tool wear in 3-milling process, very few are on 5-axis milling and bull-nose mills. This paper presents cutting forces with various cutting conditions as well as tool wear patterns in five-axis milling super alloy, which is essential to cutting vibration and defelction analysis of thin-walled complex surfaces parts. The roles of lead angle and tilt angle in five axis milling were investigated, which provide data for NC program edit. In addition, experiments in this research proved that tool wear played affected cutting forces outstandingly.Therefore, tool wear played an very important role in tool change.

Abstract: In this paper, Taguchi method was applied to design the cutting experiments when end milling Inconel 718 with the TiAlN-TiN coated carbide inserts. The signal-to-noise (S/N) ratio are employed to study the effects of cutting parameters (cutting speed, feed per tooth, radial depth of cut, and axial depth of cut) on surface roughness, and the optimal combination of the cutting parameters for the desired surface roughness is obtained. An exponential regression model for the surface roughness is formulated based on the experimental results. Finally, the verification tests show that surface roughness generated by the optimal cutting parameters is really the minimum value, and there is a good agreement between the predictive results and experimental measurements.